<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>

</body>
<script>
    class Person {
        constructor(name, age) {
            this.name = name;
            this.age = age;
        }
        static shuo() {
          console.log("保密保密")
        }
        say() {
            console.log("我是" + this.name);
        }

    }
    class Student extends Person {
        
        constructor(name, age, sex, grade) {
            super(name, age);
            this.sex = sex;
            this.grade = grade;
        }
        skill() {
            console.log("我是" + this.name + "我爱学习");
        }

    }

    let xm = new Student("小明", "10", "男", 50);

    
    console.log(xm);
    xm.say()
    xm.skill()
    Student.shuo()
    

</script>

</html>